I'm not sure about the logs, but I have exactly same symptoms, and while googling for solution I've came across a handful of other descriptions of a very similar problem at StackOverflow. Here are the links:
http://askubuntu.com/questions/534883/laptop-screen-goes-black-but-laptop-still-running http://askubuntu.com/questions/486257/chromium-inspect-element-causes-black-screen http://askubuntu.com/questions/543790/youtube-causes-black-screen http://askubuntu.com/questions/547149/since-updating-to-ubuntu-14-04-chromium-causes-black-screen http://askubuntu.com/questions/540910/ubuntu-screen-goes-black-after-loading-youtube http://askubuntu.com/questions/541862/black-screen-when-playing-youtube-videos http://askubuntu.com/questions/508796/ubuntu-14-04-chromium-causes-black-screen Noticeably most of these questions were posted within last month, and this corresponds to my own observations - my problem started around three weeks ago. So this all seems to be related to a recent update. Btw, I have Ubuntu 14.04 at Dell D630, Chromium 38.0.2125.111 and Unity. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1393905 Title: Graphic driver crash on youtube To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/1393905/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs